The Corinthians Arena under construction in Sao Paolo on March 25, 2014.

More than 1,000 ticket-holders for this month’s soccer World Cup in Brazil will need to exchange their tickets because of problems created by delays in completing venues on time.

Organizers contacted 1,376 fans via e-mail telling them to return for an exchange because their seats no longer exist, a FIFA spokesperson said by phone. All six of the 12 tournament stadiums that remained under construction in 2013 missed a December deadline. Six other venues missed deadlines for completion ahead of last year’s Confederations Cup. Work continues at Sao Paulo’s Corinthians Arena, which will host the opening game in five days.

“The setup for some stadiums in which tickets were requested have changed because of delays in finishing the stadiums,” the e-mail to ticket buyers said.

Buyers who’ve yet to collect their tickets won’t be affected. Fans who fail to exchange their tickets will be assisted to their new seats.

Organizers experienced the same problems at some of the venues at the Confederations Cup, a warm-up event that featured eight teams.

There are three price ranges of tickets for overseas buyers and four for Brazilian residents. The new seats will correspond with the category of tickets purchased.